The present disclosure generally relates to a system for providing haptic sensation to a user, and specifically to a sensor, which measures displacement of a haptic plate or membrane.
A conventional virtual reality (VR) system includes a headset that provides visual and audio information to the user. Additionally, in some instances, a VR system may also include some type of haptic device that provides haptic sensation to a user. For example, a VR system may have a matrix of actuators that vibrates to provide some type of localized indication to a user of the VR system. A large number of distributed actuators are needed to deliver haptic sensations over extended surfaces. This number grows with the square of the linear size. A system with one or more rows of actuators distributed around the perimeter of a thin metal surface has been demonstrated to be able to deliver haptic sensations in desired positions on the thin plate or membrane by sending waves that interfere, constructively or destructively, to generate the desired haptic sensation spatial profile. In this arrangement the actuator number required is only proportional to the linear size of the device, not its square. For example, a system with 64 perimeter actuators may require 400 actuators to achieve the same haptic sensation spatial definition over the same surface. The gain grows higher as larger device sizes are considered. Haptic devices need to account for dispersion of a vibrational wave as it passes through the haptic device plate, to avoid delivering inconsistent haptic experiences to the user.